Wellens is arguably the greatest player in Saints recent history. I say this not because of the talents he possessed but rather those he did not. No player has made more out of the limited natural gifts he was granted at birth. His success was primarily a product of superhuman willpower splashed with a fair degree of intelligence.
People forget that he could quite easily have gone the way of countless "promising but ultimately unsuitable" juniors and left the club circa age 21.
The only player who comes close in this fashion is James Roby.
Had Wellens a fraction of the physical attributes (speed, size, acceleration etc.) other players take for granted he would have smashed every record in the book.